Method and apparatus for using dynamic workload characteristics to control the scaling of the frequency and voltage of a CPU

A method of adjusting a frequency of operation for a processor, comprising: Executing a workload with a processor, is read and stored determining a number of retired instructions and a number of input / output queues events for the amount of work by a counter of input / output queues events (IOQ) or a counter retired instructions (IR); Determining based on the number of retired instructions and the number of input / output queues events, whether a performance characteristic within a desired range by a current IR count with a previous count is compared IR plus or minus a predetermined threshold; if the performance characteristic is within the desired performance range, determining a time duration of activities on the chip and a period of time with off-die for the amount of work; Determining from the two time periods if a phase shift has occurred wherein the phase shift includes a detected change in the activity of the amount of work, and if a phase shift has occurred, determining a new target frequency for the processor, wherein the new target frequency is determined according to a desired size of acceptable performance degradation.